Intraarticular osteoid osteomas account for approximately 13% of osteoid osteomas. The hip is the commonest location of intraarticular osteoid osteomas.

We present 16 patients with intra-articular osteoid osteomas of the hip treated with RFA. These were 13 men and 3 women, with a mean age of 27 years (range, 16–48 years). Eight osteoid osteomas were located in the femoral head, 6 in the femoral neck, and 2 in the acetabulum.

The approximate mean duration of the procedure was 82 min (range, 50–125 min). The mean hospitalization time was 8.7 h (range, 6–12 h). All patients had pain improvement within the first 24 h. Five patients had pain relief within the first 3 days, 9 patients within the first week, and 2 patients within 2 weeks post-procedural. Twelve patients continued to have some restriction of their physical activities up to one month after the operation. All patients returned to their previous status of physical activity within the first 2 to 3 months post-procedural. At the latest follow-up, there were no residual or recurrent symptoms. Five patients complained for mild pain, which was probably due to hip synovitis that resolved within a week. One patient experienced transient paresthesias and pain in the buttock at the site of the trocar and electrode insertion.

Intra-articular osteoid osteomas have clinical and imaging features significantly different from those seen in extra-articular lesions. CT-guided percutaneous RFA is a simple minimally invasive, safe and effective method for most intra-articular osteoid osteomas.